氧化鋅是一種具有寬能隙(Eg=3.37 eV)及大的激子束縛能之半導體材料，因此在光電材料上深具發展潛力。透過不同的製程可得到不同形貌之氧化鋅奈米結構，其中多孔氧化鋅奈米結構由於具有高表面積之特性，近年來許多研究將其應用於工作面積需求較大之元件上，如光感測器、氣體感測器及染料敏化太陽能電池等。然而現階段多孔氧化鋅奈米結構的成長，多為多晶結構，或是雖為單晶結構但卻非沿C軸呈規則排列(well-aligned)成長，且孔隙度亦無法有效控制。
本實驗利用一種新穎的製程方式，結合濺鍍和水熱法製程，在氫氣與氬氣混合氣體的還原氣氛下作熱處理，成長出規則排列且具有良好結晶性質之多孔氧化鋅奈米結構，同時藉由退火溫度的控制，可得到不同孔隙度之氧化鋅奈米結構，在形貌上則可得到各別獨立之多孔氧化鋅奈米柱以及海綿狀(sponge-liked)的緊密排列多孔柱狀晶，利用SEM觀察水熱法各項參數的改變對於氧化鋅奈米結構形貌的影響，以及後續熱處理對孔洞的大小和分佈之影響，輔以電子精密天秤觀察孔洞形成所需之臨界溫度，而XRD及TEM之分析說明了多孔氧化鋅奈米結構具有良好的結晶性質，最後利用PL和拉曼光譜對不同孔隙度之氧化鋅做光性分析。

ZnO is a promising material with potential applications in electric and optoelectronic devices, due to direct wide bandgap (Eg=3.37 eV) semiconducting properties and large exciton binding energy. Various morphologies of ZnO could be obtained by different processes. Porous ZnO is one of the structures which exhibits high surface area, and has been applied to the devices such as photo detectors, gas sensors, DSSCs, and etc. However, there are still lack of methods to synthesizing porous semiconductor nanostructures with good crystallinity and uniformity up to now.
In this study, we demonstrate two types of ZnO porous nanostructures with excellent crystallinity and large-area uniformity only by hydrothermal process followed by thermal annealing under Ar/H2 mixture gas; meanwhile, the porosity can be controlled by annealing time and temperature. The SEM was used to observe the influence of different parameters of hydrothermal process on ZnO’s morphology, and the distribution of pore and pore size under different annealing conditions. We also used high precision electronic balance to observe the critical temperature while the pores were formed, and the good crystallinity and uniformity of porous ZnO nanostructures were proved by XRD and TEM analyses. Finally, the optical characteristics of ZnO with different porosities were analyzed by Photoluminescence and Raman spectroscopy.

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